#region Copyright

// The contents of this file are subject to the Mozilla Public License
//  Version 1.1 (the "License"); you may not use this file except in compliance
//  with the License. You may obtain a copy of the License at
//  
//  http://www.mozilla.org/MPL/
//  
//  Software distributed under the License is distributed on an "AS IS"
//  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
//  License for the specific language governing rights and limitations under 
//  the License.
//  
//  The Initial Developer of the Original Code is Robert Smyth.
//  Portions created by Robert Smyth are Copyright (C) 2008.
//  
//  All Rights Reserved.

#endregion

using System.Collections.Generic;
using NoeticTools.StateEngine.Exceptions;


namespace NoeticTools.StateEngine.Rules
{
    public class StateRules<TContext, TState, TStateEvent> :
        IStateRules<TContext, TStateEvent>
    {
        public StateRules(TState state)
        {
            State = state;
            Rules = new List<IStateRule<TContext, TStateEvent>>();
        }

        public List<IStateRule<TContext, TStateEvent>> Rules { get; private set; }

        public TState State { get; private set; }

        public void AddRule(IStateRule<TContext, TStateEvent> rule)
        {
            Rules.Add(rule);
        }

        public void OnEvent(TStateEvent stateEvent)
        {
            var handled = false;

            foreach (var rule in Rules)
            {
                if (rule.RunsOnEvent(stateEvent))
                {
                    rule.Run();
                    handled = true;
                }
            }

            if (!handled)
            {
                throw new StateEngineEventException(string.Format("{0} state does not have rule for state event {1}",
                                                                  State, stateEvent));
            }
        }

        public void OnEvent<T>(TStateEvent stateEvent, T arg)
        {
            var handled = false;

            foreach (var rule in Rules)
            {
                if (rule.RunsOnEvent(stateEvent))
                {
                    rule.Run(arg);
                    handled = true;
                }
            }

            if (!handled)
            {
                throw new StateEngineEventException(
                    string.Format("{0} state does not have rule for parameterizes state event {1}",
                                  State, stateEvent));
            }
        }

        public void OnEntering()
        {
            foreach (var rule in Rules)
            {
                if (rule.RunsOnEntering())
                {
                    rule.Run();
                }
            }
        }

        public void OnEntering<T>(T arg)
        {
            foreach (var rule in Rules)
            {
                if (rule.RunsOnEntering())
                {
                    rule.Run(arg);
                }
            }
        }
    }
}